Issue #187 download button no longer shown if the app is not in play store

app/src/main/java/com/github/yeriomin/yalpstore/fragment/details/ButtonDownload.java

@@ -30,6 +30,7 @@ public class ButtonDownload extends Button {
     @Override
     protected boolean shouldBeVisible() {
         return !Downloader.getApkPath(app.getPackageName(), app.getVersionCode()).exists()
+            && app.isInPlayStore()
             && (!isLatestVersion() || activity instanceof ManualDownloadActivity)
         ;
     }